FUNGI: RUSTS. 



191 



407. Uredospores can produce successive crops of uredospores. — Tue uredo- 

 spures arc carried by the wind t<> otlier wheat or grass plants, gern:iinate 



Fig. 21S. 

 Section through leaf of barberry at point affected willi the cluster-cup stage of the wheal 

 rust; spermagonia abo\"e, a:cidia below. (After Marshall-Ward-) 



furm mycelium in the tissues, and httur tlic pustules with a second crop uJ 

 uredospores. Several successive crops of uredospores may be developed in 



Fig. 210. 

 A, section through sorus of black rust of wheat, showing teleutospores, B, njycelium 

 bearing both teleutospores and uredospores. 1 After de BarjM 



one season, so this is the form in which the fungus is greatly multiplied and 

 widely distributed. 



